The
recent advances in the field of composite materials make the use of Fiber
Reinforced Plastic (FRP) an effective
solution to upgrade and retrofit of
deficient structural members. Due to the wide range of bonding process of the
patch to the structural elements, there is a need to evaluate performance of
the patch under load application especially if imperfection occurs during the
bonding process. A two dimensional evaluation of both good and defective patch
repairs of structural elements was performed in this paper. The analysis is
carried out on 0.6-inch wide strips extracted from a full scale panel repaired
in accordance with an approved structural engineering standard. The
experimental program was extended to evaluate elements with a perfect bond
patch and to patch with internal defect between the patch and the parent
materials. The considered defects were 1-inch wide flaw between the sixth ply
and the parent material. A finite element model was developed to evaluate the
stress field within and adjacent to the patch area. Due to the thin nature of
the patch, the developed model is based on a geometric nonlinear formulation.
Experimental results are being used to validate and guide the analytical
approach. Results of the program will be presented to quantify the effectiveness
of the patch repair in structural upgrading applications.